Your baby was sleeping well — then suddenly everything fell apart. This is a sleep regression. It's not your fault, it's not permanent (mostly), and there are things that actually help.
| Age | Duration | Cause | Severity |
|---|---|---|---|
| 3–4 weeks | 1–2 weeks | First developmental leap | Moderate |
| 2 months | 1–3 weeks | Social development | Moderate |
| 4 months | 4–8 weeks | Permanent sleep architecture change | ⚠️ Severe |
| 6 months | 2–4 weeks | Teething, solids | Moderate |
| 8–10 months | 3–6 weeks | Separation anxiety, crawling | Moderate |
| 12 months | 2–4 weeks | Walking, first words | Moderate |
| 18 months | 2–6 weeks | Language explosion, independence | Moderate |
| 2 years | 2–6 weeks | Self-awareness, autonomy | Moderate |
Sleep architecture permanently changes to adult-like cycles. Every 45–50 minutes, baby partially wakes. Without self-soothing skills, they'll call for you every time.
This is the best moment to start sleep training. The brain is now developmentally ready to learn self-settling. Any approach — Ferber, chair method, fading — works better now than at any other age.
Baby is learning to crawl and stand, and separation anxiety peaks. The brain processes motor skills during sleep — baby may literally "practice" crawling in their sleep.
Practice the skill that's disrupting sleep during awake time. If baby stands up and can't get back down — practice sitting from standing during play. Clear, consistent goodbye rituals reduce separation anxiety.
Vocabulary triples in a matter of weeks. Baby also discovers the word "no" — and uses it at bedtime. This is normal development, not defiance.
Give controlled choices ("which book tonight — this one or that one?"). Baby feels in control; you keep the structure. Bedtime and routine stay unchanged.
| Sign | Regression | Illness |
|---|---|---|
| Fever | No | Often yes |
| Appetite | Normal or increased | Reduced |
| Daytime mood | Normal or excited | Lethargic, clingy |
| Onset | Gradual (2–5 days) | Sudden |
| Duration | 2–6 weeks | 3–10 days |
No — regressions are a normal part of development. But babies with self-settling skills handle them much better: regression lasts 1–2 weeks instead of 6.
Baby returns to their pre-regression sleep patterns. Or, if you worked on self-settling during the regression, they actually sleep better than before.
The app detects sleep anomalies and flags when a regression is starting — so you can respond with a plan, not panic.
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